The hot dog, a staple of American culture, traces its roots to German immigrants who brought weisswurst, bockwurst, and blutwurst to the United States in the 19th century. By the 1890s, it became completely associated with ballparks, according to Bruce Kraig, author of "Hot Dog: A Global History." The famous Fourth of July hot dog eating contest in New York further tied the food to the nation's birthday. The National Hot Dog and Sausage Council identifies 19 regional varieties, including the Cleveland "Polish boy" and the Chicago dog with its seven traditional toppings.